More than 170,000 acres of primary rainforest in the Peruvian Amazon have been destroyed in the past 5 years due to small-scale gold mining. This is 30 percent more than has been previously reported, according to new research carried out by scientists at Wake Forest University's Center for Amazonian Scientific Innovation (CINCIA).

The team, based in the Madre de Dios region of Peru, initially came up with a new method to identify those areas specifically affected by small-scale mining. They then combined existing CLASlite forest monitoring technology and Global Forest Change data sets on forest loss to produce a deforestation detection tool that is 20-25 percent more accurate than methods previously used.

"The scale of the deforestation is really shocking," says Luis Fernandez, executive director of CINCIA and research associate professor in the department of biology. "In 2013, the first comprehensive look at Peruvian rainforest lost from mining showed 30,000 hectares. Five years later, we have found nearly 100,000 hectares of deforested landscape."

So what does that 170,000 acres look like? Take New York's Central Park, then line up 200 of them and you'd have a good idea.

The effect of this small-scale mining on the environment is devastating. These small, artisanal mining crews do not set out expecting to hit seams rich with gold, but instead collect up the tiny gold flakes scattered throughout the rainforest. Their modus operandi is to clear the land of trees or dredge the river sediment, and then use mercury to extract the precious metal out of the dirt. This trail of destruction leaves the landscape devoid of most vegetation, with the toxic mercury having a catastrophic effect on any remaining plant and animal life. "There's enough gold in the landscape to make a great deal of money in a struggling economy," Fernandez says. "You just have to destroy an immense amount of land to get it."

It's not hard to see how this has happened. In the mid 2000s construction began on the Interoceanic Highway, a 2,603 km (1,617.4 mi) route connecting Peru and Brazil. What was once inaccessible remote rainforest became a relatively easy commute providing work opportunities for many poor communities in the Andean Highlands. To compound the problem, this type of small-scale mining does not require any heavy machinery or any great financial outlay.

Looking at satellite pictures, the devastation caused by this type of mining can be indistinguishable from natural wetland areas. Miles Silman, Associate Director of Science for CINCIA and Director of Wake Forest's Center for Energy, Environment, and Sustainability (CEES) explains that both CLASlite and the Global Forest map use different kinds of information from light waves to show changes in the landscape to give us a better insight into affected areas. "Combining the two methods gives us really good information about the specific kind of deforestation we're looking for."

CINCIA's aim is that this tool will ultimately be used to identify ways to reduce the damage caused by small-scale mining, through a partnership with Peru's Ministry of the Environment. "We want to integrate high-quality scientific research into the processes the government is using for environmental conservation in Madre de Dios," Fernandez said. "If they can institutionalize these technological innovations, they can more reliably address threats to the rainforest. You have to respond quickly and you have to respond effectively."

An animation showing the acceleration of deforestation in recent years can be seen below.